luvluvS4

I was driving in 95 degree weather and my temperature reading went all the way down to -54 degrees. I lost my AC. I let the car cool down for about a half hour and then it fixed itself.

Has anyone else had issues with this? My car is a 2001 S4. Thanks.

Zawarudo

Easiest thing to check is the ambient temp sensor, mounted in front of the a/c condenser, middle area of the car towards the bottom. If you shine a flashlight through the lower front grille you can see it. I don't see many of those going bad, but I wouldnt rule it out either.

osiris07lv

Ha ha mine is doing the same thing (01.5 S4) i was also thinking the ambient temp sensor is the culprit. . haven't changer it yet. . . if you do before me let me know if id does the trick thanks

luvluvS4

Interesting yours does that too. I assume it was temporary like mine and then fixed itself?

I'm not going to do anything unless it really messes up. It seems okay now.

jumpnofear

My 2001.5 is having AC issues as well. Different than yours but as folks are discussing it I'll ask -

Has anyone had success using Vag-Com as a means of diagnosing HVAC issues? I have put the head unit into diagnose mode and the read out is interesting but greek to me.

My problem is with either a different sensor or the actual blend actuator - it seems to continue to cycle open and closed (AC then no AC). My goal would be to see if it is the sensor, head unit or the actual door mechanism w/o buying the wrong part and tearing up my dash in the process.

osiris07lv

Yes it has a mind of its own, one min its +85 out the next its -45 then after a while it goes back. . happens every so often